Results 11 to 20 of about 1,305,934 (203)

A Theoretical Formulation of the Hammett Equation [PDF]

Transactions of the Kansas Academy of Science (1903-), 1952
the rates of over two hundred reactions with the structure of the reactants. The equation as it stands now is applicable only to reactions of aromatic compounds and their derivatives. The Hammett equation is usually written, k 0, k p iog,'-- = po" k0 is the specific reaction rate constant for a given reaction with an unsubstituted reactant, k is the ...
Gallup, Gordon A, Gilkerson, W.R., Jones, M.M.   +2 more
openaire   +3 more sources

A Special Case of the Hammett Equation [PDF]

Transactions of the Kansas Academy of Science (1903-), 1954
k=rate constant for a reaction of a substituted compound ko=rate constant for the reaction of the unsubstituted compound =--constant specific for the substituent p=constant specific for the reaction Hammett has shown that it is necessary to restrict the use of this equation to series of reactions in which the entrophy of activation is constant if the ...
Gilkerson, W.R., Gallup, Gordon A, Jones, M.M.   +2 more
openaire   +3 more sources

Cross-Dehydrogenative Coupling Reactions With Redox-Active Guanidine Reagents. [PDF]

Chemistry
ABSTRACT Cross‐dehydrogenative coupling (CDC) reactions are attractive and environmentally friendly ways to form new C‐C and other element‐element bonds. Here, we report the first CDC reactions triggered by a redox‐active guanidine reagent. N‐phenyltetrahydroisoquinoline and derivatives with electron‐donating and withdrawing substituents at the N ...
Walter P, Hübner O, Himmel HJ.
europepmc   +2 more sources

Bis(thienyl)ethenes with α-methoxymethyl groups. Syntheses, spectroscopic Hammett plots, and stabilities in PMMA films [PDF]

, 2023
A series of bis(thienyl)ethenes (BTEs) possessing perfluorocyclopentene backbones and methoxymethyl groups (MOM) in the 2/2'-positions of the thiophenes was prepared and examined.
Andreas Schmidt, Adams, Jörg, Schewe, Marvin, Jörg Adams, Nagorny, Sven, Christian Rembe, André Eitzeroth, Schmidt, Andreas, Marvin Schewe, Thea Weingartz, Weingartz, Thea, Eitzeroth, André, Sven Nagorny, Rembe, Christian   +13 more
core   +1 more source

Remote substituent effects on catalytic activity of metal-organic frameworks: a linker orbital energy model

npj Computational Materials, 2023
The Hammett equation is commonly used to theoretically depict the remote electronic effects of substituents on catalytic activities of metal nodes of metal-organic frameworks (MOFs).
Zhenzhen Wang, Huan Meng, Xuejiao J. Gao, Jia-Jia Zheng, Xingfa Gao   +4 more
doaj   +1 more source

Reduction Potential Predictions for Thirty-Seven 1,4-di-N-Oxide Quinoxaline-2-Carboxamide Derivatives with Anti-Tuberculosis Activity

Compounds, 2023
The ability for density functional theory with the B3LYP functional with the lanl2dz basis set to predict the 1st (Wave 1) and 2nd (Wave 2) reductions of the diazine ring in a series of thirty-seven (37) 1,4-di-N-oxide quinoxaline-2-carboxamide ...
Faranak Pooladian, Philip W. Crawford, Jonathan M. Kessler, Garrett R. Casey, Christina M. Ragain   +4 more
doaj   +1 more source

Estratégias para estudo das correlações de energia livre em acoplamento aril-aril de Suzuki: elucidando ciclos catalíticos através da equação de Hammett

Química Nova, 2012
The present work deals with the study of the correlation of free-energy developed in a catalytic system for Suzuki coupling, by way of the Hammett equation.
Gilber Ricardo Rosa
doaj   +1 more source

An Easy Synthesis of Monofluorinated Derivatives of Pyrroles from β-Fluoro-β-Nitrostyrenes

Molecules, 2021
The catalyst-free conjugate addition of pyrroles to β-Fluoro-β-nitrostyrenes was investigated. The reaction was found to proceed under solvent-free conditions to form 2-(2-Fluoro-2-nitro-1-arylethyl)-1H-pyrroles.
Alexander S. Aldoshin, Andrey A. Tabolin, Sema L. Ioffe, Valentine G. Nenajdenko   +3 more
doaj   +1 more source

Assessing the nucleophilic character of 2-amino-4-arylthiazoles through coupling with 4,6-dinitrobenzofuroxan: Experimental and theoretical approaches based on structure-reactivity relationships

Journal of Saudi Chemical Society, 2020
A kinetic study of the reactions of potentially bioactive 2-amino-4-arylthiazoles with highly reactive 4,6-dinitrobenzofuroxan (DNBF) is reported herein in acetonitrile solution. The complexation reaction was followed by recording the UV–vis spectra with
Reem A. Alenzi, Nizar El Guesmi, Mohamed R. Shaaban, Basim H. Asghar, Thoraya A. Farghaly   +4 more
doaj   +1 more source

Synthesis, Acidity Constants and Tautomeric Structure of the Diazonium Coupling Products of 2-(Benzylsulfanyl)-7H-purin-6-one in Its Ground and Excited States

Molecules, 2011
A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and ...
Hosam A. Saad, Farag M. Altalbawy, Elham S. Darwish, Mosselhi A. Mosselhi   +3 more
doaj   +1 more source